Post your thoughts and links relating to the foundations, justification and social impacts of the scientific examination of the natural world, computing, religion, society, economics or other fields of mental endeavour. History of science posts also most welcome.

In a nutshell, this subreddit is for all the thinking around and about science. Not so much the science itself (unless it provokes philosophical questions).

Many of Popper's ideas are fascinating to me. I have found that he has made several good points about induction. I am wondering how well he has solved the problem of induction and how much modern science has incorporated his ideas. How much of science behaves in the way Popper theorized it should? Where have they diverged, and why?

One divergence that sticks out to me is when Einstein predicted that there would be a lensing effect caused by the sun's mass on the light of the stars behind it years before it was ever observed. The divergence itself comes from the fact that the observation which followed Einstein's predictions is largely cited as a confirmation of Einstein's theories of relativity (which Popper maintained cannot happen). Whether the scientists of the day were right or wrong to see this evidence as confirmation, they did, and look where we are now. Sometimes, science doesn't behave in the neat and analytic way that Popper said it does.

It was, at minimum, a corroboration of Einstein's theory, which is very different than a confirmation.

It is the duty of those that think 'confirming evidence' means the theory is more probable than had the 'confirming evidence' not been uncovered to argue for that position, rather than a case of an increase in the degree of confidence of scientists in theories.

The first is radical, and must face the problem of induction and related problems of confirmation; the second is trivial: it is a matter of psychology that scientists feel more confident in a theory when faced with corroborating evidence.

On a related matter: many scholars may cite the Eddington experiment as a confirmation of Einstein's theory, but if these scholars are mistaken, then so much for the work of those scholars. In other words, a citation agreed-upon by a group as an instance of confirmation cannot itself be evidence that confirmation takes place. That's putting the cart before the horse.

I think that there is emergent property of the collaborative/competitive nature of science that is already fairly close to what Popper proposed (this is true of many other institutions, to greater or lesser extents, such as philosophy, literature, and art). Many collaborative/competitive institutions--even some religious institutions--are very Popperian/Feyerabendian/Lakatosian/Kuhnian in structure.

That said, while this may be true of institutions as a whole, individual members may each shore up their theories from criticism as best they can, claim that they search for confirmations, say that unfalsifiability or uncriticisability is a virtue, or act in other ways that are far from virtuous. I mean to say, the left hand doesn't know what the right hand is doing--and actively thinks the right hand is doing something else entirely, if that makes any sense.

It's of my opinion that there was no problem to begin with--it is a pseudo-problem stemming from a question with the mistaken hidden assumption that we make justified positive inferences about the unobserved from the observed.

No, science is like a Necker cube or a duck-rabbit: while some scientists see the method of science as practicing induction and fully believe science could not be otherwise, the 'institution' of science cares little of what they believe, and operates just as well even if many scientists think of themselves as practicing induction.

Think of a world where the human body was inhabited by sentient cells à la the children's film Osmosis Jones: Bill Murray doesn't care what his cells think, so long as they properly serve their function. Bull Murray: the institution of science; the opinions of individual cells: the opinions of individual scientists.

Interesting. Would you say that you align more with Feyerabend in that respect? As I understood, he also advocated doing away with the demarcation of science altogether. My grasp on his view is an impoverished one, but I'm interested in learning.

I'm closer to Bartley, Miller, and Lakatos than Feyerabend. Rather than thinking the problem dissolves, it's just a smaller version of a larger problem, demarcating rational from irrational behavior, or desirable from undesirable choices, and so on.

I'm not sure how I should answer your question. I'll try as follows...

It could be either cultural or genetic or some combination of the two. Going up from the most vulgar to the most cultivated, there might be the following:

Confirmation bias seems cross-cultural, and looks like a good explanation as to why most individuals think empirical evidence can give positive support to scientific theories. You see people failing the Wason selection task all over the place, for example.

Some of the cultural end is a matter of the implicit metaphysical theories in our language. It's just a matter of speaking that we say 'evidence' or 'proof' in positive ways. It's just intuitive to speak of emeralds being green and not grue. (Rorty's argument in Philosophy and the Mirror of Nature gives a similar account with the mirror analogy.)

From the second, individuals may think there is evidential support for prior reasons that take this intuition that construct a better explanation by using the probability calculus. That's where you get subjective interpretations of Bayesianism, Carnap's attempt, and so on.

The Bayesians think that we have good reasons for the support of our priors, or that they will all approach a happy medium over time. That's bullshit. Our priors are still dependent on our intuitions on the structure of the universe, so any single instance of preference is but a choice based on our metaphysical commitments. Evidence serves no function in that instance. Over the aggregate, it serves only a negative function. Why? For problems with the probability calculus dealing with strictly universal statements. These problems have been covered time and again in the whole Popper & Miller theorem fiasco.

But overall, there just hasn't been an adequate explanation to Hume's problem, Goodman's riddle, Hempel's paradox, related problems in the underdetermination of theory by evidence, and so on. So people that think we use induction refuse to accept the modus tollens. Their thinking might be approximated as the following:

we use induction.

problem X that undermines 1.

but we use induction.

ergo, problem X is mistaken or induction is even more mysterious than we thought!

Possibly. Of course, they're not justified in any way (see: evolutionary epistemology or genetic epistemology for fallible synthetic a priori intuitions). Or conjectures, IBE's, myths, stories. Call them what you want.

The main problem with Popper's refutation of induction is that it would in practice make it impossible to predict anything at all.

Lets say we have a number of competing but unfalsified theories for a given phenomenon. This means they have all 'survived' previous criticism in accordance with Popper's corroboration criteria. In order to apply them in practice, however, we need to choose between them, and so Popper would have us choose the one that has survived the best. How then do we know which one is the most corroborated theory? We choose the one that has survived the most elaborate attempts at falsification. But this is a purely inductive mode of reasoning: we assume that theories that have survived criticism in the past are most likely to do so in the future.

Popper's arguments thus face a problematic dilemma. Either the argument against induction rests upon an inductive proof, or we have to accept that there is no rational method of choosing between competing theories in science.

Corroboration is not ampliative. It's more like a scorecard. That is, it's just a measure of past performance and doesn't entail anything about future success. Popper said this explicitly.

Even though a theory may be highly corroborated by the evidence, logical consequences of the theory will not necessarily inherit that corroboration. For example, Einstein believed his theory entailed determinism, the notoriously untestable hypothesis that for everything that happens there are conditions such that, given those conditions, nothing else could happen.

According to Popper's notion of corroboration, determinism is untestable and, therefore, uncorroborable. There is no evidence which could, in principle, falsify determinism, and so neither can there be evidence to corroborate it. It's degree of corroboration must always be zero.

So just because a theory is corroborated, it does not follow that such corroboration is dispersed evenly among its logical consequences. In particular, the presently unverified predictions of a theory are not themselves corroborated by the existing evidence.

Put another way, my observation of the sunrise this morning might corroborate my expectation that the sun rises each morning, but it does not corroborate my expectation the sun will rise tomorrow morning. Although this seems highly counterintuitive, it has a rather straightforward explanation. That is, my observations of past sunrises were not tests of my expectation that the sun will rise tomorrow, and so nothing is corroborated.

The rule to remember is if evidence corroborates a theory, then the negation of that evidence would, in principle, falsify the theory. Since my expectation of observing the sunrise tomorrow would not be falsified by my failure to observe sunrises in the past, past observations of sunrises cannot corroborate the expectation of a sunrise tomorrow morning.

The confusion here stems from a fallacy of decomposition. That is, supposing what is true for the whole is true for its constituent parts. In this case, while my expectation of a sunrise every day may be highly corroborated, it does not follow that any particular logical consequence of that expectation is also highly corroborated. When we break down our theories into their constituent parts (such as past and future predictions, or metaphysical and falsifiable implications), we find that corroboration is not evenly dispersed.

So when you say that preferring the most corroborated theory is 'a purely inductive mode of reasoning', you are mistaken, because Popper's understood well that any measure of corroboration (or probabilistic support) is non-inductive. It may resemble inductive reasoning, but it's not.

Popper's claim that we should prefer the most corroborated theory is a methodological rule to assign critical preference. It is not intended to be any kind of logical inference from the evidence, because, according to Popper, no such inference is possible, i.e. it's not induction. Put another way, while a measure of corroboration is logically derived from the probabilities and logical relations between theory and evidence, the methodological preference for the most corroborated theory does not and cannot be in any way be so derived, and Popper never pretended that it could.

First, that particular solution to the pragmatic problem of induction is one of at least three that came from the Popperian school, but I'll only get into one more because I am hung over, tired, and in need of a cup of coffee. (As an aside, this solution is found first in the second volume of the Popper issue of Library of Living Philosophers series, which is worth checking out if you get the chance.)

What exactly is the problem? If evidence can play only a negative function, then when sorting between the theories we have left over, which theory should we prefer? Popper gives a methodological--not epistemological--solution to the problem: use the theory that survives the most elaborate attempts at falsification! Popper notes in the second volume of LLP that whichever theory is chosen will not then mean that we are able to give credence to it having a high degree of objective verisimilitude, nor will we have reason to believe that the theory will continue to work as well as it has in the past. To think so would be to fall into the inductivist trap of the pragmatic problem. Popper reverses the role of argumentation to that of his famous 'conjectures and refutations': Popper presents a proposal, then others are free to find some fault in it. If the proposal is criticisable in principle and no faults are found, the we can tentatively adopt it if we so choose, especially when alternatives don't survive similar criticisms. Now, is there a problem with the proposal to choose the theory that survives present criticism over the theories that have not? If so, then voice it. Popper does not claim to justify this proposal or give good reasons for thinking that it will be a good method. Instead, to flip van Fraassen's turn of phrase on its head, we choose the best of the present lot, even if the best is still bad. It makes no sense to choose the worst of the lot, does it?

Miller advanced the more negativist methodological rule, that we are disallowed from choosing the theories that have not survived attempts at falsification. We are then free to adopt, without reason or justification, without the ability to explain why the choice was made, whichever theory we choose. This fits within van Fraassen's own voluntarist stance where one is never compelled on pain of irrationality to adopt a scientific theory; rather, one is permitted to make the non-rational choice to adopt a theory from amongst the theories that have survived criticism. Lucky for us there are so few theories available that fit this criteria and also other criteria we adopt (for example, on the negative side: they don't have unexplained ill-behaved predicates; on the positive side: they unify disparate fields when alternative theories do not), leaving us with just a few interesting theories to prefer.

Hope that explanation makes sense, and if you have any more questions, I'd love to continue. But excuse me, I'm off to coffee and ibuprofen my brain.

Well, that is refreshing. The training of scientists has nothing to do philosophy and the goal of a scientist is distinct from that of a philosopher. Scientists are trained to seek the next data point. That is the only truth to seek. The Truths they acknowledge are not certainties but are accumulations of data so established, both inductively and deductively, that, as a limit approaches a finite number, the data points approach some truth. Scientists do not look for certainty. They do not expect it. They understand induction and they, actually, hope that some new data will upset an established "truth."

I read, somewhere, that science split from "natural philosophy" when they started asking not "How?" but "How much?". Instead of rationalism (and I am still looking for a truth, that is not a tautology or mathematical formalism, to spring forth from some rational argument), empiricism drives science. Scientists are not concerned with rationalism even as it applies, and it does without doubt, to them. They would be much more interested in a study of scientists that actually analyzed their work and study and methods.

Thats an interesting question. Technically, I think it certainly is possible for science to continue to progress without any philosophy. The problem, though, is how you define "progress".

An understanding of the methods, history, and ultimate goals of an institution is vital to keeping the institution together and "progressing" on the right track. Think about how much time and research expenditures could be saved, for instance, if scientists knew how to recognize the signs of a faltering paradigm. And think about how difficult it would be to protect science from corporate, political, and ideological intrusions unless scientists were more or less united with a clear sense of the purpose and proper function of science as demarcated from other human pursuits. How difficult would it be for scientists to honestly engage the public on science without a thorough understanding of its foundations, strengths and limitations? These are all philosophical concerns.

I also can't help but feel that philosophy and science both originate from the same human motivations to understand and explain the universe and ourselves. You can't have one without inadvertently laying foundations for and encouraging the other as well. I first got interested in the philosophy of science, for instance, by wondering what would happen if I turned my scientific skepticism on science itself. And we all know that science originally developed as a branch of philosophy that sought to use rigorous philosophical and mathematical thought to explain the natural world.